Determining the Maximum Rate of Potassium Fertilizer on Oil Palm (Elaeis guineensis Jacq.) in Production in Southeastern Côte d'Ivoire

In the southeastern of Côte d'Ivoire, ferralsols are characterized by poverty in exchangeable bases, especially potassium, which appears to be the predominant mineral element for oil palm cultivation. In this study, we used improved palm cultivars treated with different rates of potassium fertilizer to determin the effect on oil palms. The experiments were conducted on the CNRA station in La Mé and PALMCI in Ehania (Côte d’Ivoire), following a system block system design comprising of five treatments and four repetitions. Treatments included 5 rates of potassium fertilizer (T1, T2, T3, T4, T5) corresponding to 1; 1.5; 2; 2.5; 3 kg of KCl/tree/year. This study indicates that the different rates of KCl applied, had influence on all of the experimental parameters, namely: yields (TR) and its components (NR; PR and PMR). Yields on the Ehania plantation were significantly higher than those on La Mé. Yield ranged from 18.8 Tons/ha/year (T1) to 22.1 Tons/ha/year (T3) in La Mé, and from 21.2 to 25.6 tons/ha/year in Ehania. The theoretical maximum rates were 2.4 kg of KCl/tree/year in La Mé, compared to 1.9 kg/tree/year on the Ehania plantation. Therefore, these rates will be used in the future extension of potassium fertilizer, in the cultivation of oil palm, in the southeastern of Côte d'Ivoire.